Silicon-on-insulator (SOI) substrates, such as fully depleted SOI (FDSOI) or radio frequency SOI (RFSOI) are used for various integrated circuit (IC) applications. Such SOI substrates include a thin surface crystalline or silicon layer separated from the bulk substrate by a buried oxide (BOX). Typically, IC applications include high voltage (HV) transistors, such as extended drain metal oxide semiconductor (EDMOS) transistors. However, the thin surface substrate of SOI substrates, such as RFSOI and FDSOI, are not amenable to accommodate HV transistors, such as EDMOS. This results in difficulties in integrating HV transistors on SOI substrates. For example, conventional techniques for integrated HV transistors on SOI substrates require complex processing to make them compatible. Complex processing results in increased cost.
The present disclosure is directed to HV transistors, such as EDMOS which are easily integrated on SOI substrates, such as RFSOI or FDSOI substrates.